Reduced complexity optimum detector for block data transmission systems using Lattice Sphere Decoding technique

The complexity of the exhaustive search decoding technique such as Maximum Likelihood Block Detection (MLBD) grows exponentially with the size of transmitted data. In this paper, a Lattice Sphere Decoding (LSD) technique is proposed for detection in block data transmission systems (BDTS). Simulation results at 10dB channel SNR of BDTS with LSD using block size of 20 performs are near Hybrid Micro Genetic Algorithm (HMGA) and slightly inferior than the exhaustive search technique using the channels with spectral nulls. In term of complexity, the proposed LSD technique requires only 460 and 126 objective functions evaluation using radius selection based on Babai Estimation (BE) and off-line observation respectively, while the HMGA and exhaustive search requires 3750 and 220 objective functions evaluation respectively.